Currently, a metal substrate may be joined with a plastic through the following three methods:
(a) using an adhesive to join a metal substrate with a formed plastic;
(b) improving the characteristics of a plastic; or
(c) forming holes on a surface of a metal substrate by electro-chemical etching treatment, and injection molding a plastic on the surface of the metal substrate to join the metal substrate with the plastic.
However, all of the above methods have their shortcomings. For example, using an adhesive to join the metal substrate and the resin will cause poor adhesion force, poor resistance to acid or alkali, and the thickness of the adhesive will affect the size of the final product.
A better method for producing a metal-plastic composite is desired.